Open-hearth furnace



July 1, 1930. A T KELLER 1,769,843

OPEN HEARTH FURNACE Filed Dec, 5, -1921 `2 Sheets-Sheet l A. T. KELLER July l, 1930.

OPEN HEARTH FURNACE Filed Dec. 5, 1921 2 Sheets-Sheet 2 f ff/ Patented July 1, 1930 UNITED STATES PATENT oFFlcl:v

ALBERT T. KELLER, OF BETHLEHEM, PENNSYLVANIA, ASSIGNOR, BY MFBNE ASSIGN- MENTS, TO OPEN HEARTH COMBUSTION COMPANY, A CORPORATION OF NEW JERSEY OPEN-HEARTH FURNACE Application. led December 5, 1921. Serial No. 520,044.

The present invention relates to reverberatory furnaces and particularly to reversible regenerativeffurnaces of the type used in the manufacture of steel by the open-hearth process.

The object of the invention is to provide a furnace of this class having a novel and improved end construction by means of which the incoming fuel and the resulting flame may be more thoroughly controlled, and the rate of production of the furnace increased without at the `same time cutting down the length of its effective life. A furnace having the improvements incorporated therei'n is illustrated in the accompanying drawings in which:

Figure 1 is a vertical longitudinal section through the improved regenerative furnace;

Figure 2 is a section on line 2-2 of Figure 1;

Figure 3 is a similar section but showing certain of the parts adjusted to different positions;

Figure 4 is also a view similar to Figure 2 but showing .a further adjustment of the parts; and

Figure 5 is a plan view of the furnace partly broken away to show its interior.

Both ends of the furnace are preferably alikey and in the drawings one end only has therefore been illustrated. The hearth is indicated at 10 and has an upwardly inclined end portion 10 while the reverberatory roof 11 has a downwardly inclined portion 11',

throat 12 the floor of the furnace is substantially horizontal and the roof again slopes upward, as is usual in modern open hearth constructions.

Horizontal flues leading to air and gas regenerating chambers (not shown) are indicated at 13 and 14 respectively, the air flue 13 being connected by two substantially vertical uptakes 15 to ports 16 in the floor of the furnace in rear of the throat. The flue 14 has an uptake 17 leading therefrom which turns forward above the furnace floor and terminates in a gas outlet port 18,

The throat is provided with a throttling device by means of which its effective area may be materially varied. This device comprises essentially two dampers 19, 19, pivotally supported at 20, 20 to rotate about parallel axes which are closely adjacent and disposed equidistantly from the longitudinal center line of the furnace, and directly above the gas outlet ort 18. Each damper 19 comprises a metallic frame 21 substantially triangular, though having curved sides as shown in Figures 3 and 4, and brickwork or a wall of refractory material supported by this frame. Chains 22 are connected to the dampers at points remote from the pivotal axes and by means of these chains, which are suspended from operating mechanism', the dampers may be raised and lowered.

The roof 11 is slotted to receive the dampers when raisedby4 chains 22, and the side walls of the throat are curved and provided with grooves to receive the outer edges of the dampers so that products of combustion cannot pass around such edges. The outer edge 21 of each frame 21 is arc shaped, the arc being centered about the pivotal axisl of the damper and the grooves in the side walls of the furnace are correspondingly arced so that as the damper is adjusted its outer edge 21 never escapes from these grooves. The portions 212 of the frames 21 which are adjacent the gas port, are also arc'shaped andare, when the dempers are lowered, centered approximately about the center of suoli port so that in the closed position of the dampers, as shown in Figure 2, the port through which air must pass to the combustion chamber is substantially arc-shaped and the stream of incoming air completely covers the stream of incomin gas. The air stream is also directed by t e dampers 19 to impinge on the stream of gas'for all intermediate adjustments of the dampers, the air port maintain,- ing' substantially its arced form.

In Figure 3 the dampers are shown partially elevated to permit an increased flow of air, and in Figure 4 the dampers are shown completely elevated, and the throat 12 unrestricted. This is the position which the dempers occupy at the outlet end of the furnace in order to provide a large and unrestructed outlet port for the products of combustion. With such a large outlet it is possible to supply gas or air, or both, under pressure.

The products of combustion cannot escape through the grooves in the top of the furnace, inasmuch as the dampers occupy and fill these grooves at all times, the inner ends of the frames 21 being in rolling Contact with each other. This is true for all adjustments of the dampers. The grooves in the bottom of the furnace into which the lower corners of the dampers are received are of such depth that the dampers may' be raised through a considerable distance without lifting these corners from the grooves, so that the effective area of the airport may be considerably varied without destroying its shape.

Different types of regenerative furnaces may be equipped with the improved throttlinr devices and the invention may be em-.

bodied in various modifications.

Having thus described the-invention what I claim as new and desire to secure by Letters Patent is:

1. An end construction for regenerative open hearth furnaces having a throat lead-- ing into a combustion chamber, a gas port centrally arranged for delivering gas to the throat, means for delivering air to the throat at the sides ofthe gas port, and dampers movable transversely of the throat for regulating the air passing therethrough, said dampers having an arcuate lower surface so as to have a substantially semi-circular port between them for all adjustments thereof.

2. An end construction for regenerative open hearth furnaces having a throat leading into a combustion chamberthrough which fuel may be introduced or products of combustion may escape, and means for `varying the effective area of the throat including two substantially triangular dampers pivotally hung centrally of the furnace and from its roof, said dampers being adapted to be raised and lowered to vary the effective area of the throat opening. v

3. An end construction for regenerative open hearth furnaces having a throat leadin into a combustion chamber through whic fuel may be introduced or products of combustion may escape, and means for varying the effective area of the throat including two dampers pivotally mounted .to move transversely into or out cf the throat through an opening in the roof., the damp-ers being designed constructed to fill the ipenings at all tim to prevent the escape gases fram the f 'i 4. An end construction for regenerative open hearth furnaces having a throat leadin into a combustion chamber through whic fuel may be introduced or products of combustion may escape, and means for varying the effective area of the throat including two dampers pivotally mounted to move` trans-- signature.

ALBERT T. KELLER. 

